In light of energy prices and environmental concerns, processes for the production of fuels from renewable feedstocks are needed. The most common process involves producing ethanol from corn. Unfortunately, using corn and the like as precursors competes with food and feed supplies.
Some processes employ lignocellulosic biomass as a feedstock because it is readily available and competitively priced. Lignocellulosic biomass often comprises polymeric carbohydrates (cellulose and hemicelluose), complex poly-aromatics (lignin), extractives and ashes and thereby does not compete with food and feed supplies.
WO 2007/103858, incorporated herein by reference, describes using biomass-derived carbohydrates to form alkanes. An aldol condensation of acetone with furfural or 5-hydroxymethyl furfural (HMF) followed by reduction of the coupled product in hydrogen gives alkanes having from approximately 8 to 18 carbon atoms. Unfortunately, the described process has numerous disadvantages. For example, the reactions often require a high strength base. Moreover, the low degree of branching of the derived alkanes also results in a low octane numbers which limit their use in izasoline. Therefore, the production of practical gasoline fuels from biomass using prior art methods requires additional processing steps adding to the cost and inefficiencies.
Accordingly, new processes are needed for use in making biofuels which are more efficient and more cost effective.